/Engine/Source/Runtime/SlateCore/Public/Application/SlateApplicationBase.h
void GetSafeZoneSize ( [FMargin](API\Runtime\SlateCore\Layout\FMargin) & SafeZone, const [UE::Slate::FDeprecateVector2DParameter](API\Runtime\SlateCore\Types\FDeprecateVector2DParameter) & OverrideSize )